Construction machine

ABSTRACT

A construction machine having an engine arranged along a counter weight, wherein the intake air pipe of the engine is passed between the counter weight and the engine without the need of installing the counter weight spaced from the engine, so that the counter weight protrudes outwardly less. This is accomplished by a piping space ( 44 ) of a recessed shape formed in the surface ( 36 ) of the counter weight ( 18 ) facing the engine ( 4 ) allowing the intake air pipe ( 28 ) to pass therethrough.

TECHNICAL FIELD

The present invention relates to a construction machine and, morespecifically, to a construction machine in which an engine is arrangedalong a counter weight which is a balance weight of the constructionmachine.

BACKGROUND ART

Hydraulic excavators and wheel loaders which are typical constructionmachines are equipped with a counter weight at a rear end portion of amachine body to maintain a balance with the weight of working equipmentinstalled on the front side of the machine body and with a load exertedthereon. The counter weight is so heavy that it occupies a large portionon the machine body. On the inner side of the counter weight in themachine body, an engine such as a diesel engine which is a power sourceof moving the construction machine is arranged along the counter weight.

The counter weight defines the contour of the rear end portion of themachine body of the construction machine. In order to maintain good rearview from the operator in a cab installed on the machine body, in orderthat the counter weight will not come in contact with the obstacles inthe surrounding and in order to decrease the turning radius of theoutside edge of the machine body, which pivots, of a constructionmachine such as a hydraulic excavator, therefore, it is desired toinstall the counter weight on the inside of the machine body as close aspossible to the engine side so will not to much protrude rearward and sowill not to much protrude upward, either.

The engine is equipped with heat-exchanging units such as a fan forproducing the cooling air, a radiator through which the cooling airflows, an oil cooler and the like. Further, an air cleaner which is anintake air filter of the engine is installed on the side of the outsideedge of the machine body opposite to the engine with the heat-exchangingunits interposed therebetween in order to take in the open air of a lowtemperature. The construction machine is operated under severe loadconditions and under severe environmental conditions. Therefore, theheat-exchanging units are formed in a large size and occupy a largespace for installation on the machine body. The intake air pipeconnecting the air cleaner to the engine is arranged between theheat-exchanging units and the counter weight in the portion of theheat-exchanging units or above the heat-exchanging units.

DISCLOSURE OF THE INVENTION

The conventional construction machine of the form as described above,however, involves problems that must be solved as described below.

(1) Rearward Protrusion of the Counter Weight

The intake air pipe of the engine has a relatively large diameter. Topass the intake air pipe between the engine and the counter weight, apiping space must be secured by broadening therebetween. For thispurpose, the counter weight is moved toward the rear side of the machinebody for installation. Therefore, the rear end portion of the machinebody protrudes by an amount by which the counter weight is movedrearward. This gives the possibility of hindering the rear view of theoperator and causing an increase in the turning radius of the outsideedge of the machine body, whereby a problem will arise that the workingefficiency of the construction machine deteriorates.

(2) Protruding Upward of the Machine Body

When the intake air pipe is passed above the heat-exchanging units inorder to avoid protruding rearward of the counter weight, the hood ofthe machine body covering the upper side of the engine becomes high andthe machine body protrudes further upward, hindering the rear view fromthe cab.

The present invention was achieved in view of the above-mentionedcircumstances, and its technical assignment is to provide a constructionmachine in which an engine is arranged along a counter weight, whereinthe intake air pipe of the engine is passed between the counter weightand the engine without the need of installing the counter weightseparated away from the engine, so that protruding outward of thecounter weight can be lessened.

Namely, according to the present invention, as a construction machine tosolve the above-mentioned technical problems, there is provided aconstruction machine comprising a counter weight which is a balanceweight of the construction machine, an engine arranged along the counterweight and an intake air pipe connecting the engine to an air cleanerwhich is an intake air filter of the engine, wherein a piping space of arecessed shape is formed in the facing surface of the counter weightfacing the engine so as to pass the intake air pipe therethrough.

Further, by passing the intake air pipe through the piping space formedin the counter weight, the engine and the counter weight can be arrangedwithout being separated away from each other.

In a preferred embodiment, the surface facing the engine is formed beingcurved in a direction to cover the engine.

The counter weight is so formed as to cover the engine and consequently,the weight of the engine efficiently works as a balance weight, making,as a whole, it possible to decrease the protruding rearward of thecounter weight.

Further, a fan driven by the engine and a heat-exchanging unit throughwhich the cooling air produced by the fan flows are provided, the aircleaner is installed on the side opposite to the heat-exchanging unitwith respect to the engine, and the intake air pipe is arranged passingthrough the piping space in a portion where the heat-exchanging unit andthe counter weight are neighboring each other.

By passing the intake air pipe through the piping space of the counterweight in a portion of the heat-exchanging unit that occupies a largespace, the problem of protrusion of the counter weight is eliminated.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a hydraulic excavator which is a typicalconstruction machine constituted according to the present invention;

FIG. 2 is a view illustrating, on an enlarged scale, a portion ofchiefly an engine and a counter weight while removing some members fromthe swing table, as viewed from a direction of an arrow A in FIG. 1;

FIG. 3 is a rear view illustrating a portion of chiefly the engine whileremoving the counter weight from the swing table, as viewed in adirection of arrows B—B in FIG. 2;

FIG. 4 is a perspective view of the counter weight as viewed from theupper side in a direction of an arrow C in FIG. 2; and

FIG. 5 is a sectional view illustrating chiefly a portion of the counterweight as viewed from a direction of arrows D—D in FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

A construction machine constituted according to the present inventionwill now be described hereinafter in further detail with reference tothe accompanying drawings illustrating a preferred embodiment of ahydraulic excavator which is a typical construction machine.

Referring to FIG. 1, a hydraulic excavator which is generally designatedby numeral 2 includes an under carriage 4 and a swing table 6 mounted onthe under carriage 4 so as to freely turn about a swing axis 5 whichextends substantially vertically. A cab 10 and a working equipment 12having a bucket 12 a are arranged on the front side (left side inFIG. 1) on a swing table frame 8 of the swing table 6. On the rear side(right side in FIG. 1) of the cab 10, there are arranged an engine room16 accommodating an engine 14 and a counter weight 18 which is a balanceweight, at the rear end portion.

With reference to FIGS. 2 and 3, in the engine room 16 is arranged anengine 14 which is constructed by a diesel engine on the swing tableframe 8 via a plurality of mounting rubbers 20 in the right-and-leftdirection (up-and-down direction in FIG. 2) along the counter weight 18.The counter weight 18 is arranged over the full width of the swing table6 in the right-and-left direction and is mounted on a pair of mainframes 9 and 9 of the swing table frame 8.

The engine 14 is equipped, on one end side thereof (lower end side inFIG. 2), with a fan 22 that is driven by the engine 14 to produce thecooling air and a heat-exchanging unit 24 which is arranged facing thefan 22 and through which the cooling air flows. The heat-exchanging unit24 comprises a radiator for cooling the cooling water of the engine 14and an oil cooler for cooling the operation oil of the working equipment12, and is formed in a rectangular, nearly square, parallelopiped shapewith its surface facing the fan 22. As viewed from an end, theheat-exchanging unit 24 is formed in a size large enough to meet thesize of the engine 14, so that the engine 14 endures severe operatingconditions under which the hydraulic excavator 2 is operated. Asindicated by an arrow F (FIG. 2), the cooling air produced by the fan 22flows in toward the heat-exchanging unit 24 from the outside of theswing table 6, flows through the heat-exchanging unit 24, flows aroundthe engine 14, and is exhausted to the outside of the swing table 6. Anair cleaner 26 which is an intake air filter of the engine 14 isarranged in space into which the cooling air flows between theheat-exchanging unit 24 and the left side (lower side in FIG. 2) of theswing table 6. The air cleaner 26 is mounted on a member (not shown)forming the swing table frame 8 or the engine room 16. The air cleaner26 is connected, through an intake air pipe 28, to the housing on theair-intake side of a turbo charger 30 which is installed on the centralupper portion of the engine 14. The housing on the air-exhaust side ofthe turbo charger 30 is connected, through an exhaust pipe 34, to amuffler 32 provided at an end side of the engine 14 on the side oppositeto the end side where the heat-exchanging unit 24 is provided. Theintake air pipe 28 is arranged in nearly the horizontal direction alongthe side surface of the heat-exchanging unit 24 on the side of thecounter weight 18. The intake air pipe 28 is formed of a steel pipe or arubber pipe, and has a relatively large diameter among the pipesarranged around the engine 14.

With reference to FIGS. 4 and 5 together with FIGS. 1 to 3, the counterweight 18 is formed of cast iron as a unitary structure. Viewed from theupper side (state shown in FIG. 2), the counter weight 18 has its wholeshape curved in a direction to cover the engine 14, has a width in theright-and-left direction (up-and-down direction in FIG. 2) which issubstantially the same as the width of the swing table 6, and has aheight in the up-and-down direction (up-and-down direction in FIG. 3)which is substantially the same as a height of from the upper surface G(FIG. 1) of the engine room 16 up to the lower end portion H (FIG. 1) ofthe swing table frame 8. The surface 36 facing the engine 14 comprises acentral flat surface portion 36 a extending nearly in parallel with theengine in the right-and-left direction and tilted surface portions 36 band 36 b each tilted toward the side of the engine 14 from the right andleft ends of the flat surface portion 36 a. The rear end 38 side of thecounter weight 18 is formed in nearly an arcuate shape as a whole tomeet the curvature of the surface 36 facing the engine. A pair ofrecessed portions 40 and 40 are formed in the lower central portions ofthe counter weight 18 on the side of the surface 36 facing the engine,so as to allow the counter weight to mount on the pair of main frames 9and 9 of the swing table frame 8. In each recessed portion 40 are formeda mounting surface 40 a and a plurality of threads 40 b for mounting.The counter weight 18 is mounted on the main frames 9 and 9 of the swingtable frame 8 by using the mounting surfaces 40 a, threads 40 b andbolts 42.

A recessed piping space 44 is formed in the flat surface portion 36 a ofthe surface 36 facing the engine, the recessed piping space 44 extendingin the horizontal direction so as to correspond to the position wherethe intake air pipe 28 is arranged and being open in a rectangularshape. The piping space 44 is formed in the shape of a trapezoidalgroove with the open side expanding. The piping space 44 is of such asize that allows the intake air pipe 28 to be arranged maintaining agap.

The intake air pipe 28 is mounted on the swing table 6 in such a waythat the intake air pipe 28 is arranged between the engine 14 and theair cleaner 26 beforehand and then, the counter weight 18 is mounted.Or, the counter weight 18 is first mounted on the main frame 9 and then,the intake air pipe 28 is arranged between the engine 14 and the aircleaner 26 passing through the piping space 44.

Described below is the function of the above-mentioned constructionmachine.

(1) Intake Air Pipe

The intake air pipe 28 passes through the piping space 44 formed in thecounter weight 18. Unlike the prior art, therefore, the counter weightneeds not be moved rearward for passing the intake air pipe. Since theprotrusion is decreased by an amount by which the counter weight wouldhave been moved, the rear view of the operator is not impaired and,besides, the turning radius R (FIG. 2) of the outside edge portion ofthe machine body can be decreased. Moreover, since the intake air pipe28 does not pass above the heat-exchanging unit 24, such a problem iseliminated that the upper surface G (FIG. 1) of the engine room 16become so high as to interrupt the rear view.

(2) Counter Weight

Since the surface 36 of the counter weight 18 facing the engine iscurved in a direction to cover the engine 14, it is allowed to move theengine 14 toward the rear side of the machine body to approach thecounter weight 18 in the back-and-forth direction of the swing table 6.Therefore, the weight of the engine 14 can be effectively utilized as acounter weight. Accordingly, the weight of the counter weight itself canbe decreased correspondingly, so that it becomes possible to decreasethe amount of protruding rearward.

Though the invention was described above in detail by way of anembodiment, it should be noted that the present invention is in no waylimited to the above embodiment only but can also be modified or changedin a variety of ways within the scope of the present invention, asdescribed below.

(1) Piping Space

In the embodiment of the present invention, the piping space 44 in thecounter weight 18 has an opening of a rectangular shape with its crosssection being a trapezoidal shape. However, the shape of the opening andits cross-sectional shape as well as the size thereof may be suitablychanged depending upon the shape of the intake air pipe 28 and aposition where the intake air pipe 28 passes through.

(2) Counter Weight

In the embodiment of the present invention, the surface 36 of thecounter weight 18 facing the engine is curved in plan view (FIG. 2). Thesurface 36 of the counter weight 18 facing the engine, however, may becurved in side view (FIG. 5).

(3) Counter Weight

The surface 36 of the curved shape facing the engine may be formed flatin parallel with the engine 14 over the whole surface thereof dependingupon the structure and size of the machine body of the constructionmachine.

(4) Counter Weight

In the embodiment of the present invention, the counter weight 18 isformed of a casting as a unitary structure. The counter weight 18,however, may be formed in the shape of a hollow container using a steelplate or the like, and may be filled with scrap iron, concrete or thelike therein.

(5) Construction Machine

Though the embodiment of the present invention has dealt with thehydraulic excavator 2 as a construction machine, the invention can beadvantageously used for any construction machine such as a wheel loader,a crane truck or the like, which is equipped with the counter weightwhich is a balance weight.

In the construction machine constituted according to the presentinvention, there is provided a construction machine having an enginearranged along the counter weight, wherein the intake air pipe of theengine is passed between the counter weight and the engine without theneed of installing the counter weight separated away from the engine, sothat the protruding outward of the counter weight is lessened.

What is claimed is:
 1. A construction machine comprising: a counterweight which is a balance weight for the construction machine, thecounter weight having a facing surface; an engine positioned adjacent tothe facing surface of the counter weight and having an intake air pipeconnecting an air intake of the engine to an air cleaner which includesan intake air filter for the engine, a piping space recessed in thefacing surface of the counter weight, the intake air pipe extending inthe piping space; a fan driven by the engine and a heat exchanging unitproximate the engine through which cooling air produced by the fanflows, said air cleaner being installed on a side of the engine oppositeto a side of the engine on which said heat-exchanging unit is installed,said intake air pipe being arranged to pass a portion thereof throughsaid piping space adjacent to where said heat-exchanging unit and saidcounter weight are proximate one another.
 2. The construction machineaccording to claim 1, wherein the counter weight has a surface facingsaid engine which is curved in a direction to cover said engine.